Magnet-shield.



0. E. F. AHLM.

MAGNET SHIELD.

APPLICATION FILED JAN. 18, 1908.

Patented Dec. 15, 1908.

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1O as are used for lifting and conveying loads and useful Improvement in of which the following is a full, clear, and

UNITED sTATEs PATENT OFFICE.

cHARLEsE. F. AHLM, or CLEVELAND, orno, ASSIGNOR TO ELE'c'rRIc CONTROLLER & SUPPLY COMP-ANY, A CORPORATION or OHIO.

MAGNET-8H1 LD.

Application filed January 13, 1908. Serial 0. 410,5l8.

To all whom it may concern: A

Be it known that I, CHAR-LES E. F. AJ-ILM,

.acitizen ot the UnitedBtates, residing at Cleveland, 111 the county of Cuyahoga and State of Ohio, have inventeda certain new exact description.

Theob ect of the pre'sentinvention is to prov de ,a shield for lifting-magnets, such of small articles, like scrap,' -pig iron, nuts 'by merely lowering the magnet Such a magnet, for example, is. shown 111 my ,prior patent No. 837,174of November 27, 1906.

My purpose is, particularly shieldcapable of being tend ng between the.poles.ot' the lifting magnet, in such manner as to hold the material to be'li'fted' away from the magnet coils, at

.a distance greater than the mere thickness of the metalot the shield, and thus cause the magnetic flux to enter more deeply into the pile. In addition to the above stated function, the shields are adapted to protect the coils and support them in their proper position. These, and other advan-v tages, will appear from the specification below, reference being had to the accompanying drawings, in whichform of shield constructed according to the and two' coils.

principles of my invention, and shown as attached to a bell magnet having three poles the shield, a portion of it being broken away. In the form shown in Fig. 1, the shield A is constructed to be attached to atripole magnet B having two coils C, G' properly interposed between its poles,-the outer poles of the magnet being lower than the t it seats on the lower facesofthe pole-pieces,

- On the upper side of theshield I provide at whereby attachment to the magnet is readily made,'screws being used for this purpose.

suitable spaced intervals supporting ribs D adapted to receive the load of the coils" interposed between the adjacent pole pieces.

Specification of Letters Patent.

Magnet-Shields,

to providea attached toand ex- 1 Fig. 2 is a plan view of Patented Dec. 15, 1908.

These ribs are. preferably broadened at the 'top to afford azpropcr bearing surface, while ltS central web D is somewhat reduced to eliminate much metal as posslble. The

manner and provided with. the supporting ribs adapted tosustain the coils, it will be in my statement of invention and produces the results sought in the simplest and least expensive manner. According to this con str-uction, not only will this single element serve as-a support forthe coils, but, by rea-' son of its shape and construct1on, .1t Wlll hold the material which is being lifted by tl'ie magnet at a substantial distance from the coil, which distance may be increased to any extent shortof that which would. cause the reluctance along the vpath through the materialtobecome so great as to result in'an undue amount of leakage across the space between the face of the shield and the coil above.

These shields are, obviously, especially adapted to lifting magnets where an outer pole hangs below the inner pole, and in which the coil, at its outer circumference, is igure 1, 1s a vertical cross section of a at an appreciable distance above the outer pole face. Were a mere fiat plate, without means such as would insure the proper spacing of the lifted material away from thecoils, used beneath the coils in the magnets seen that it possesses the functions outlined shown, not only would-there be a'certain awkwardness in attaching thejsame, but the material lying against the Hat plate would aatford asliortpath'itor the magnetic'flux,

through which it Would'pass, skimming the surface of the pile without being forced to enter ,very deeply into it; Practically, none of the magnetic lines would pass oil the lower end of the outer pole, since they would find a shorter path of less'reluctance immediately beneath the c'oil.. It will, therefore, be seenlthat the shield particularly increases the eflectiveness of bell magnets, above stated.

1. In a lifting magnet, an inner pole and an outer pole, the active face of the outer Having. thus described my invention, 1 claim:

"pole being lower than the active face of the taining the said winding, the said shield being thicker 'near its outer edge than at its inner edge. r v

2. In a hftmg magnet, an inner pole and an outer pole, the active face of the outer pole being lower than the active face of the inner pole, a magnetizing winding between the said poles, and an annular shield for retaining the said winding, the said shield having ribs with a greater depth near the outer periphery of said shield than at the inner periphery thereof.

3. In a lifting magnet, an inner pole and an outer pole, the active face of the outer pole being lower than the active face of the inner pole, a magnetizing winding between the said poles, an annular shield for retaining the said winding, there being an annular space, wider at its outer edge than at its inner edge, between the said winding and the said retaining shield, and means on the retaining shield for supporting the said winding.

t. In a liftingmagnet, an inner pole and an outer pole, the-active face of the outer.

. pole being lower than the active face of the inner pole, a magnetizing winding be.- tween the sand poles, an annular sh1eld.for

retaining the said winding, there being an annular space, wider at its outer; edge than at its inner edge, between thesaid winding and the said retaining shield, and ribs on the retaining shield for supportin g the said 1 winding.

5'. In a. lifting magnet,.an inner pole and an outer pole, the'active' face'ofvthe outerpole being lower than theactive face of the annularspace, wider atitsouter edge than v at the inner edge, between the said-winding and the said retaining shield.-

6. In a lifting magnet, an inner pole,'a'n outer pole,'the active face of thelatter being lower than the active face of the inner pole,

a magnetizing winding between the said poles, and means covering the said winding and spacing the' material' attracted by the magnet further below the outer edge of the winding than'below the inner edge thereof. 7 In a lifting magnet, an inner pole, an outer pole, the active face of the latter being lower than the active face of the inner pole, a magnetizing winding between the said poles, and means including anon-mag- .netic plate andribs supported thereby for covering the said winding and spacing the material attracted by the magnet further be low the outer edge of the winding than below the inner'ed'ge thereof.

In testimony whereof, I hereunto affix my signature in the presence of two witnesses CHARLES E. F. AHLM. Witnesses:

J. M. \Voohwann, H. R. SUILLIVAN. 

